The present invention relates generally to the art of window coverings and more specifically relates to cutting machines and methods for cutting window coverings to specified lengths.
Retail outlets frequently sell many different types of window coverings such as draperies, curtains, venetian blinds and shades. These window coverings generally extend horizontally across a window opening and are typically sized to accommodate the dimensions of the window opening. One popular type of window covering is a window shade having a head rail, a bottom rail and a window covering material between the head rail and the bottom rail. Common window covering materials include slats, such as PVC slats, or fabric. One problem with such window shades is that the width of the head rail, the bottom rail and the window covering material must be customized to match the exact dimensions of the window opening. In response to this problem, a number of options have been developed so that consumers may obtain customized window shades which are sized to fit a specific window opening.
In accordance with a first option, a customer typically visits a specialty shop or department store and places an order for customized window shades. This option requires the customer to first measure the window opening and submit the measurements to a salesperson. The salesperson will then submit the order to a factory or distribution center where the window shade is cut to the specified length. This option is rather time consuming, because the customer must make at least two visits to the retail outlet in order to obtain the customized product, i.e. a first visit to place the order and a second visit to pick up the product. In addition, this particular option is relatively expensive.
A second option involves selecting the window shade from a stock of pre-sized shades maintained at the retail establishment. Typically, only certain standard sizes are carried because some window openings, especially in newer homes and offices, are of standard dimensions. These pre-stocked, standardized window shades are usually much less expensive than those obtained from custom specialty shops because stocked shades may be mass-produced in an economical manner. In addition, the cost to the consumer is reduced because there is no need to perform a cutting or sizing operation at the retail establishment.
A third option has recently evolved. This particular option involves the in-store sizing or cutting of the window shades to match the exact window dimensions specified by the customer. Various machines and methods for performing these tasks are disclosed in U.S. Pat. Nos. 5,339,716; 5,037,253; 5,456,149; 4,993,131; 5,072,494 and 5,103,702. These various disclosures have been generally inadequate at providing systems for efficiently and accurately sizing window shades to specified lengths. For example, most of the systems disclosed are too complex to be operated by a typical retail salesperson having an average degree of training. In addition, many of these systems require numerous steps in order to cut the window shade, i.e. the head rail is cut in a first cutting operation and the window covering material is cut in a second cutting operation. Further, these systems, and particularly the cutting blades of these systems exert a tremendous amount of force upon the window shade being cut which often results in the cut ends of the shades being uneven, chipped or cracked. These defects produce a final product of inferior quality.
Thus, there is a need for a cutting apparatus for window shades capable of efficiently customizing window shades to fit window dimensions specified by customers. There is also a need for a cutting apparatus for cutting a window shade to a specified length, whereby the entire window shade, namely the head rail, the bottom rail and the window covering material are all cut simultaneously in a single cutting stroke, thereby saving time and reducing operator errors. Moreover, the cutting apparatus should produce a final product having a high-quality, professionally-cut appearance. Applicant is presently the exclusive licensee of such an improved cutting machine which is disclosed in U.S. patent application Ser. No. 08/627,015 entitled xe2x80x9cEnd Trimming Device For Blindsxe2x80x9d, the disclosure of which is hereby incorporated by reference herein. Another improved cutting device is sold by the Applicant, Springs Window Fashions, under the trademark xe2x80x9cCrystal Pleat Cut-Down Machine.xe2x80x9d
However, still further improvements would be desirable.
In accordance with certain preferred embodiments of the present invention, a cutting apparatus is provided for cutting a window shade to a specified length. The window shade preferably includes a head rail, a bottom rail and a window covering material or covering material. The window covering material or covering material typically includes a fabric or slats provided between the head rail and the bottom rail. The head rail and the bottom rail preferably comprise a substantially rugged material, such as extruded plastic, which can be readily cut to specified lengths.
The cutting apparatus preferably includes a base having a top or cutting surface and a frame overlying the cutting surface of the base. The frame is preferably mounted to the base to form a rigid structure. The frame and the cutting surface define a receiving area therebetween for receiving one or more window shades which will be cut in the cutting apparatus. A cutting assembly is slidably mounted to the frame for sliding along a movement axis toward and away from the receiving area. The frame preferably includes one or more guide tracks which are angled with respect to the cutting surface of the base and the cutting assembly is slidably mounted in the guide tracks so that the movement axis is diagonal to the cutting surface of the base. The cutting assembly includes a cutting blade having a cutting edge facing the receiving area. The cutting apparatus also includes a mechanical element, such as a driver, which may be operated to impart sliding motion to the cutting assembly. The driver may include a rack and pinion gear arrangement, a ratcheting mechanism, a screw-activated element, a pneumatic element or an electrical-motor operated device. In one particular preferred embodiment the cutting assembly includes a rack having a plurality of teeth. A pinion, having a plurality of teeth at a periphery thereof, is rotatably mounted in the frame. The pinion is matingly engaged with the rack so that when the pinion is rotated, the pinion imparts sliding motion to the cutting assembly to move the cutting blade diagonally through the receiving area for cutting the window shade to the specified length. As the cutting blade moves toward and away from the cutting surface, the cutting edge remains at all times substantially parallel to the top of the cutting surface.
The base may include a support guide, provided over the cutting surface thereof, for guiding movement of the window shade across the cutting surface of the base and towards the receiving area. In preferred embodiments, the support guide includes a mandrel which engages at least one of the head rails or bottom rails and which most preferably engages the head rail during cutting operations. The mandrel extends along the cutting surface of the base from a first end of the cutting surface to a second end of the cutting surface. The second end of the cutting surface is preferably adjacent the cutting blade.
In certain preferred embodiments the base includes a clamp assembly for securing the window shade over the cutting surface of the base. The clamp preferably includes a clamp block having a threaded bore, a threaded shaft which is capable of being rotated and a crank handle. The threaded shaft has a first end which is threadably connected to the clamp block and a second end which is rotatably connected to the crank handle. Rotation of the crank handle moves the clamp block into and out of engagement with the window shade. The crank handle is preferably rotated in a clockwise or counter-clockwise direction so as to apply a clamping force to the window shade. In other preferred embodiments the clamp may include a pneumatic device, an electrically operated device, a screw device, a ratcheting device or a weight.
The cutting blade is preferably provided at the second end of the cutting surface and has a longitudinal axis which is substantially perpendicular to the longitudinal axis of the guide rail. The cutting blade has a first face which is substantially flat and a second face which includes a pocketed portion. The pocketed portion of the cutting blade is preferably the only section of the blade which engages and cuts the window shade. The pocket is substantially thinner than the area of the cutting blade which surrounds the pocket. The pocketed portion includes a tapered region which is contiguous with the cutting edge and which extends up and away from the cutting edge. The tapered region has a first tapered section or bevel which extends from the cutting edge. The first tapered section and the substantially flat first face define a first acute angle. The tapered region includes a second tapered section which extends from the first tapered section. The second tapered section and the substantially flat first face define a second acute angle which is smaller than the first acute angle. The substantially flat first face of the cutting blade preferably faces upstream toward the first end of the top surface of the base while the second face (i.e. the face including the pocketed portion) preferably faces downstream and away from the first end of the top surface.
The cutting blade preferably includes any material, man-made or naturally occurring, having the strength and/or durability to efficiently cut through the shade assembly, and more preferably includes carbide steel or diamond.
The cutting apparatus also preferably includes a measuring assembly adjacent and/or downstream from the cutting blade for measuring the window shade. Specifically, the measuring assembly provides a measuring tool for defining the exact length of the end portion of the window shade to be cut. The measuring assembly preferably includes a stop block which abuts against the end portion of the window shade. The stop block is connected to a cam follower which in turn is connected to the pinion so that the stop block moves away from the end of the window shade as the cutting blade slices through the window shade. By camping away, the stop block allows the cut end portion of the window shade to pivot away from the cutting blade which minimizes the forces exerted by the cutting blade upon the window shade. Thus, the stop block is movable between a first position and a second position. In the first position, the stop block abuts against the end portion of the window shade. In the second position the stop block is not in contact with the end portion of the window shade because the stop block cams away from the end portion.
Another aspect of the present invention provides a method of cutting a window shade to a specified length. In certain preferred embodiments a method of cutting the window shade includes providing a cutting apparatus having a receiving area for receiving the window shade whereby the cutting apparatus includes a cutting blade slidably mounted therein for sliding along a movement axis toward and away from the receiving area. Next, the window shade is provided in the receiving area and the cutting blade is passed diagonally through the receiving area and the window shade for cutting off an end portion of the window shade to provide a window shade having a specified length. Initially, the window shade is inserted into the first end of the cutting apparatus and slid along a cutting surface of the base toward the cutting blade so that the cutting blade overlies the end portion of the window shade which is to be cut. The measuring assembly is then utilized to determine the exact length of the end portion of the window shade being cut. Once the exact length of the end portion to be cut has been determined, the crank handle of the clamping assembly is rotated so that the clamping block moves into engagement with the window shade so as to secure the window shade between the clamp block and the guide rail. The crank continues to be rotated until the clamping block has secured the window shade over the cutting surface of the base. The pinion is then rotated to move the cutting assembly. A lever handle is preferably connected to the pinion to facilitate rotation of the pinion. Rotation of the pinion slides the cutting assembly in the angled guide tracks along the movement axis which is diagonal to the cutting surface of the base so that the cutting blade slices diagonally through the window shade. As the cutting blade slices through the window shade, the stop block cams away from the end portion of the window shade being cut so that the cut end portion is free to pivot away from the cutting blade. Because the end of the window shade being cut is free to pivot away from the blade, the compression forces exerted by the cutting blade upon the window shade are greatly reduced which greatly reduces the likelihood that the head rail or the bottom rail will crack while being cut. After the window shade has been completely cut, the direction of the lever handle is preferably reversed to return the cutting blade to its initial position. The measuring assembly moves back towards the cutting blade as the handle is returned to its initial start position. At this point the window shade may be removed from the cutting apparatus. In certain instances it may be preferable to trim or cut a second end of the window shade to a specified length. This may be accomplished by inserting the second end of the window shade into the cutting apparatus and repeating the steps described above.